- idetape_pc_t *pc = tape->pc;
- xfer_func_t *xferfunc;
- idetape_io_buf *iobuf;
- unsigned int temp;
-#if SIMULATE_ERRORS
- static int error_sim_count = 0;
-#endif
- u16 bcount;
- u8 stat, ireason;
-
- debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__);
-
- /* Clear the interrupt */
- stat = ide_read_status(drive);
-
- if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
- if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) {
- /*
- * A DMA error is sometimes expected. For example,
- * if the tape is crossing a filemark during a
- * READ command, it will issue an irq and position
- * itself before the filemark, so that only a partial
- * data transfer will occur (which causes the DMA
- * error). In that case, we will later ask the tape
- * how much bytes of the original request were
- * actually transferred (we can't receive that
- * information from the DMA engine on most chipsets).
- */
-
- /*
- * On the contrary, a DMA error is never expected;
- * it usually indicates a hardware error or abort.
- * If the tape crosses a filemark during a READ
- * command, it will issue an irq and position itself
- * after the filemark (not before). Only a partial
- * data transfer will occur, but no DMA error.
- * (AS, 19 Apr 2001)
- */
- set_bit(PC_DMA_ERROR, &pc->flags);
- } else {
- pc->actually_transferred = pc->request_transfer;
- idetape_update_buffers(pc);
- }
- debug_log(DBG_PROCS, "DMA finished\n");
-
- }
-
- /* No more interrupts */
- if ((stat & DRQ_STAT) == 0) {
- debug_log(DBG_SENSE, "Packet command completed, %d bytes"
- " transferred\n", pc->actually_transferred);
-
- clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
- local_irq_enable();
-
-#if SIMULATE_ERRORS
- if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) &&
- (++error_sim_count % 100) == 0) {
- printk(KERN_INFO "ide-tape: %s: simulating error\n",
- tape->name);
- stat |= ERR_STAT;
- }
-#endif
- if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
- stat &= ~ERR_STAT;
- if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) {
- /* Error detected */
- debug_log(DBG_ERR, "%s: I/O error\n", tape->name);
-
- if (pc->c[0] == REQUEST_SENSE) {
- printk(KERN_ERR "ide-tape: I/O error in request"
- " sense command\n");
- return ide_do_reset(drive);
- }
- debug_log(DBG_ERR, "[cmd %x]: check condition\n",
- pc->c[0]);
-
- /* Retry operation */
- return idetape_retry_pc(drive);
- }
- pc->error = 0;
- if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
- (stat & SEEK_STAT) == 0) {
- /* Media access command */
- tape->dsc_polling_start = jiffies;
- tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
- tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
- /* Allow ide.c to handle other requests */
- idetape_postpone_request(drive);
- return ide_stopped;
- }
- if (tape->failed_pc == pc)
- tape->failed_pc = NULL;
- /* Command finished - Call the callback function */
- return pc->callback(drive);
- }
- if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
- printk(KERN_ERR "ide-tape: The tape wants to issue more "
- "interrupts in DMA mode\n");
- printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
- ide_dma_off(drive);
- return ide_do_reset(drive);
- }
- /* Get the number of bytes to transfer on this interrupt. */
- bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) |
- hwif->INB(IDE_BCOUNTL_REG);
-
- ireason = hwif->INB(IDE_IREASON_REG);
-
- if (ireason & CD) {
- printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__);
- return ide_do_reset(drive);
- }
- if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) {
- /* Hopefully, we will never get here */
- printk(KERN_ERR "ide-tape: We wanted to %s, ",
- (ireason & IO) ? "Write" : "Read");
- printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
- (ireason & IO) ? "Read" : "Write");
- return ide_do_reset(drive);
- }
- if (!test_bit(PC_WRITING, &pc->flags)) {
- /* Reading - Check that we have enough space */
- temp = pc->actually_transferred + bcount;
- if (temp > pc->request_transfer) {
- if (temp > pc->buffer_size) {
- printk(KERN_ERR "ide-tape: The tape wants to "
- "send us more data than expected "
- "- discarding data\n");
- idetape_discard_data(drive, bcount);
- ide_set_handler(drive, &idetape_pc_intr,
- IDETAPE_WAIT_CMD, NULL);
- return ide_started;
- }
- debug_log(DBG_SENSE, "The tape wants to send us more "
- "data than expected - allowing transfer\n");
- }
- iobuf = &idetape_input_buffers;
- xferfunc = hwif->atapi_input_bytes;
- } else {
- iobuf = &idetape_output_buffers;
- xferfunc = hwif->atapi_output_bytes;
- }
-
- if (pc->bh)
- iobuf(drive, pc, bcount);
- else
- xferfunc(drive, pc->current_position, bcount);